Material stacker



March24, 1953 s. M. MERCIER A MATERIAL STACKER 5 Sheets-Sheet 2 Filed Feb. 3, 1949 /NVENTo/Q; 5 TAN LEY M. MERcxER,

s. M. MERCIER 2,632,558 Y MATERIAL STACKER 5 sheets-sheet 5 //vVE/\/TO/Q; STANLEY M. MERCIER,

BY A i Y. MX/@9 ATTY.

March 24, 1953 Filed Feb. 5, 1949 n o o D mf s. M. MERCIER Marchz4, 1953 MATERIAL VS'IMKER- 5 Sneets-shee1= 4 Filed Feb. 3, 1949 Q Q v G J RCIER,

STA N LEY M f Bf /AL Patented Mar. 24, 1953 `UNITED STATES PATENT OFFICE f aesaass. *Y

Stanley M; Mercier, Bexley;, `0hia, ass'gnorto; The. Jeffrey Manufacturing Gompany, a corpora-` tion of Ohio Z2 Claims.`

This' invention relates' particularly to a stacker forstacking or" dumping material', such as sand, gravel and dirtl which has; been conveyed' to a desired position by one or more belt conveyors. object ofthej invention is to provide in1` proved" interconnecting control means between a boom and atraction device, such' as a crawler tractor, which isadapted to'swing the boom in a generally horizontal plane through a substantial arc'L whereby the discharge position ofl the material maybe adjusted.

j A" further and more specic object, of the in* vention is to provide means for interconnecting a stacker frame'with the mast; postor pedestal ofa` tractor which includes a. carriage providing for`I limited rectilinear; movement between said .post and said boom` and switch means controlled thereby.

A4 further' object isA to provide mechanism as abovedescribed in which there is ball and socket means providing for limited tilting movement of `the mast or post of" the tractor relativeY to the Vboom.

Anotherk object of the invention is to provide switch meansA operable whenever a desired limite'd travel has taken place between the carriage and the` boom.

` Afurther object ofthe invention is to. provide lswi'tchimeans operable wheneverv the. boom has itilted' a. predetermined amount. p

Other obiectsofl the inventionwill' appear here.-

inaften the novel features and' combinations being set, forth in the.v appended claims.

In the accompanying drawings Fig, I ai side elevational' View of a stacker ,E including the features off my invention. and showdrawings and being taken `on the line 3--3 ofy Fig! 2..; v

.vFgf is a. sectional'lview showingv a modied double switch which'. may be substituted for th single tilt switch of Fig. 2;

Fig. 5-is alview, generally similar to Figi 23 of a modied form of universal connection between the post and carriage of the stacker;v together with aA modified form of switch and actuating mechanism therefor;`

Fig. 6 is a view in section,V thek section being taken online 6-6 of 'Fig'.v 5';

Fig. 7 is a View in section of thestructure; seen in Fig. 5, the section being taken substantially on line 1-1 of Fig. 6; and

Fig. 8 is an enlarged! view in plan showing'a portion of the switch actuating mechanism 'shown inFig.5. .i

As seen in Fig. I of the drawings, the'stacker includes a very long and large generally' horizontal boom Ii! which is fabricated from elongated structural' members and reinforcing'vertiical and diagonal members. The boom I0 carries an endless belt conveyor H which i'sadaptedj to convey material from a feed hopper I2v and dis'- charge itl overk the headpulley I3. off the con*- veyor. Such aboom is adapted particularl'yto convey granular material, such asrock, stone, dirt, gravel, sand, coal, or' any similar material which it is desired to be conveyed and' discharged. One illustration of the use of such a stacker is in connection with the removal and disposal of the overburden inv a strip coal mining operation oru in astrip iron ore mining operation. AOther illustrations aretheremoval of material" prepara- -tory to theconstruction of dams and causeway's.

swings the boom and the boom so as to providey for limited longitudinal and rectilinearmovement between theA tractor andA the boom and. also to provide a, relatively tilting movementbetween the two, since the groundv or surface over which the tractor travels may be somewhat un-f even. v j Y j .thereon on anti-friction bearings 2l. vrollers 26 of the carriage 22 project between op- -posite upper and lower ianges of a pair of to the carriage 22. Fig. 2 of the drawings, it is, of course, evident that 'the weight of the boom I 9 is normally trans- The tractor for swinging the boom is seen at I5 and is illustrated as of the crawler type. It may be controlled by an operator in the operators house I6 located on top of the boom III generally above the tractor I5.

To interconnect the tractor I5 with the boom I and provide the characteristics above mentioned, said tractor I has an elongated upwardly extending boom supporting mast, post or pedestal 1, to the upper end of which is rigidly attached a horizontal plate I8 (see Fig. 2), to which in turn there is rigidly attached a concave cup or socket I9 of what constitutes in effect a large ball and socket joint or bearing, the ball 20 of which is actually only a segment of a sphere having a lower convex or segmental sphericalY socket I9, there preferably being a hard babbitt bearing liner 2| interposed between the ball 29 and socket I9 and preferably attached to the latter as by sweating or the like.

The ball and socket connection I9, is one form of universal connection and preferably the 4`one employed in this form of my invention. Ob- ,viously in certain broader aspects of my inven- -tion other universal type connections may be employed, such as a standard universal joint or the gmbal type universal connection. Rigidly attached to and supported by the segmental ball 20 is a carriage 22 which includes a ibed plate frame member 23 which is directly con- `nected'to the upper portion of said segmental ball 20. Laterally spaced and longitudinally extendy.ing upright plates 24 are connected to the bed plate 23, said plates 24 in turn carrying laterally extending spaced axles 25 to which there is a 'roller 26 attached on each end, being mounted The four laterally spaced I-beams, rails or supporting Vtracks 28 which form an integral part of the boom I0. The inner upper and lower flanges of .the I-beams, rails or supporting tracks 28 are provided with removable wear strips or tracks 29 Ywhich hold the boom I0 against any appreciable vertical or up and down movement with respect As clearly illustrated in mitted to the carriage 22 through the rollers 26 and upper tracks 29, the rollers 26 normally being .out of engagement with the lowertracks 29. The carriage 22 also has four rollers |26 which cooperate with tracks 29 to take lateral thrust.

-From the above description it is, of course,

evident that the carriage 22 can move rectilinear- .ly or longitudinally relative to the boom I0. It Yis Vdesirable that this movement be restricted A.and `in one illustration it is limited roughly to a travel of Vve feet so that the tractor I5 will not getY too far away from its desired position of support for the boom l0. To this end there ,is preferably a pair of limit switches 30 (see Figs; 1 and 3), one located near each end of the desired travel of the carriage 22, the limit The switches The universal ball and socket joint I9, 20, 2|

xlspreferably lubricated and to this end a lubri-,

cation feed pipe 33 connected to a source of lubriinterposed bearing liner 2|.

eating uid under pressure extends through a horizontal bore in the plate I8 to a position adjacent the center thereof from which it extends upwardly to a cavity at the center of the cup or socket I9. Communicating with said cavity is a chamber 34 formed in the center bottom portion of the ball 20 to which a pressure gauge 35 is connected by a pipe or conduit 36.

Hydraulic fluid under pressure in the chamber 34 will nd its way along the bearing liner 2| and any excess hydraulic uid owing over the peripheral edge of said liner will be received in a circumferential groove 31 formed in the socket I9. Groove 31 is connected to a drain pipe or conduit 38 and preferably has an oil level gauge 39 therein.

As clearly illustrated in Fig. 2 of the drawings the opposed segmental spherical surfaces of the 4joint I9, 29 extend beyond the circumferential groove 3i but beyond said groove there is no At the periphery of the socket I9 there is a wiper 40 made of leather, rubber or the like, which is rigidly attached to the socket |9`by a metal band or the like and which has wiping engagement with the ball 2|) around a small circle thereof, thus preventing any substantial leakage of lubricating material beyond this point.

In view of the above described universal connection between the carriage 22 and the mast, post or pedestal I'I it is obvious that said carriage 22 and the boom I0 which it supports is free to tilt in any direction or universally relative to said post Il. It is evident, however, that this tilting movement should not be allowed to progress to an unreasonable extent as this might upset the tractor I5 land damage the equipment and possibly injure the operator.

The freedom of relative tilting movement, however, is desirable because of the unevenness or irregular undulations of the ground or bed over which the tractor I5 must ride. In this regard it may be stated that the universal connection provides a third point of an essential three-point support for the boom I0, it being mounted at its rear for swinging movement on a horizontal axis which is designed to prevent any appreciable lateral tilting of said boom I0.

In order to give a signal or effect a control whenever the post Il is tilted a limited safe amount relative to the boom I9, alimit switch is provided which is closed whenever said limit is reached. Said switch comprises a pair of rings 4| and 42 of conducting material which are carried in a sheathing flexible ring or continuous tube 43` of rubber or the like. The rings 4| and 42 are normally spaced apart, as illustrated in Figs. 2 and 3 of the drawings, as is provided by the dimension of the enclosing ring or casing 43. The upper ring 4| is supported bya plurality of spaced chain hangers 44 preferably provided with insulating blocks 45, thereby to insulate the ring 4| from its supporting structure. Chains 44 are in turn supported from the bed plate 23 by brackets 4B. K

As is evident from Figs. 2 and 3 of the drawings, the switch structure 4|, 42, 43 is thereby normally suspended from the bed plate 23 in a position surrounding the top plate I8 of the post or pedestal I1. Y

Tilting movement of the post I'I relative to when said post or pedestal isftilted a predetermined amount any 'direction the lower angle. v4.'I .will support the ring l2 and bring it into `contact with .the ring .4L Rings 4I and 42, therefore comprisethe two, contacts of a switch, :which switch is employed to give an suggested. l

In the operation of the device, material to be `conveyed and discharged or stacked is delivered .to the feed hopper I2 and conveyed by the belt conveyor mechanism II to .discharge over the .head pulley I3. Continuously or intermittently .during this. dischargingoperation the boom I [l -will be swung about an upright axis through any desired arc, such as 180, by the` travel of the tractor I5. I

One type of operation involves the successive swingingy of the boom orstacker, followed. by forward feeding ofthe position of the feed hopper I2,Kthereby to produce a spoilage pile over which the stacker progresses. `As the tractor I5 travels over any uneven surface `to swing the boom I9 the limited freedom of rectilinear or longitudinal .freedom of rectilinear or longitudinal movement between the carriage 22 .and the boom I 0 relieves .the pivotal` attachment for the rear end of the boom I of strains, particularly rectilinear strains along the longitudinal axis of said boom vwhich would occur if the tractor I5 wererigidly attached to the boom Il).

'I'he switch means 30, however, prevent undue relative travel between the post I'I` of tractor I5 Aand the boom I0, thus insuring that support for the boom I is maintained reasonably at the proper position.

As the tractor I moves over uneven ground, strain is not transmitted to the boom because the post I'I is `free to follow the tendency of the tractor to accommodate 'itself to the uneven or irregularly undulated ground due to the ball and Vsocket connection I9 and 29 which is the preferred form of universal connection between the carriage'22 and the mast, post or pedestal I 1, since this universal connection provides for Y' limited Vrelative tilting between the boom Ill and saidv post or pedestal I'I.

y To prevent damage which might occur in an extreme case of relative tilting, the switch 4I, e2, 43 isprovided to give an alarm or effect any desired control whenever the limit of safe tilting has beenV reached. It is thus evident that mechanism has been provided which will relieve Yconsiderableof the strain otherwise inherent inA a tractor swung boom which is adaptedto travel over uneven or irregularly undulated ground.'

@In Fig. 4 of the drawings a modified form of switch is illustrated which may he substituted for the switch 4I43. The principal feature of this modified switch is` that it is a double or duplex switch and it operates so that on a predetermined tilt one pair of contacts will be closed, which may, for example, give an alarm, Whereas if a greater tilt is realized or eifectuated a second pair of contacts may lbe actuated which, for example, may disable the driving motor` for the crawlers.

Said switch of Fig. 4 includes a ring-like enclosing sheathing or endless tube 43 of rubber jor'the like, vin which there are three enclosed -concentricrings'49, 50 and 5I, all made of conducting'material. Ring li9 is supported in the 'same mannerthat ring '4|'o`f Fig. 2 is supported.

' alarm or to ,control desired mechanism as above Fig.- 2. Ring 50-is interposed-.between` rings49 and 5I and is rigidly attached atsubstantially the center of the enclosing sheathing 48, thus being normally held out lof contact with both rings 49 and 50. ObViously,upon-a predetermined tilting of the post I'I relative to theboom IB orcarriage 22, ring 5I will first be brought into 'contact with ring 50, closing or actuatingthe switch provided by these two rings. Further tilting will lift the two rings 50 and 5I together and cause ring 5l'lV to contact ring 49, thus actuating the second switch providedby said rings 49 and 50, which may shut down the apparatus.

In Figs. 5, 6, 7 and 8 of the drawings there is illustrated a modified form of universal support for the boom lll, as well asV a different type i of switch and actuating means therefor which may be substituted for the corresponding parts shown in Figs. 1 through 3. In said Figs. 5, 6, `'I and 8 there is anupstanding elongated mast, post or pedestal 52'which is essentially the same as the mast, post or pedestal I'I and has vthe same relation with a tractor I5.

'Ihe boom I9 is provided with I-beams 53 which are essentially similar to the above described I-beams 28 and are provided with top wear tracks 54 and bottom wear tracks 55. A carriage 5B is universally supported on top of the mast 52 by right angle trunnions in a generally horizontal plane, one of which trunnions is provided by a shaft 5l journaled at opposite ends to cross axles or frame members 58 of said carriage 55, which axles 58 carry boom supporting rollers 59 on opposite ends thereof, which rollers 59 support the I-beams 53 through the wear tracks 54.

Lateral thrust is transferred from the carriage 55 to'the I-beams 53 by four laterally spaced bearing wheels 6l] carried on the bottom of the carriage 56. The shaft 5l is mounted on a pin 8l carried by spaced trunnions 82, the axis of which pin is at right angles to the axis of the shaft 51, said trunnions 82 and pin 8| being carried on a swivel plate 83 in the top housing 6I of the mast 52.

Rigidly attached to and depending downwardly from the carriage 56 are four spaced arms 52 which at their bottoms are adjustably attached to a circumscribing angle shaped ring 63, which circumscribes vthe upper endl of the mast or pedestal 52. It is evident that the ring 63 will partake of the movement of the carriage 55 and asvthe mast or pedestal 52 tilts relative to the boom I0 and carriage 5B, the position of the ring V63 will vary with respect to said post or pedestal 52.

` Near the top of the post'cr pedestal 52 and below the housing 6I there is' a pivot ring B4 'which is rigidly attached to the said post or pedestal 52 by a plurality of perinherally spaced brackets 55. plurality of bell crank levers 6B, of which there are a large number, being appropriately journaled on said ring 64, as clearly illustrated in Fig. 6 of the drawings. The levers 66 have downwardly extending arms which together form a Askirt, something like a grass skirt, surrounding the mast or post`52. Said downwardly extending arms normally contact the inner edge of the actuating ring 63.

y The levers 66 also have inwardly and pref- Lerably downwardly sloping arms which normally rest upon a stop ring 61 carried by the brackets B5. Normally resting on the inwardly extending armsof'the levers 66 isan actuating ring 68 which surrounds theV post'52`. DiametricallyU ex- The ring 64 pivotally supports a vFigs. and 6 is as follows.

tending right angle cross rods 69 extend between opposite sides of the ring 68 and through slots in the post 52.

At the center of the ring 68, which is normally at the center of the post 52, there is a block to which said rods 69 are attached. The block. 'Hl is provided with a downwardly extending hook 1| which` ishooked to a substantially vertically hanging actuating rod *i2 which at its bottom is pivotally attached to a pivoted cross lever 13, which ycross lever i3 is pivotally attached at one' end toa bracelet on the post or pedestal 52 and at the `other end carries a pair of cam. operated switches 14 and 15, there being one adjacent each side thereof. The switches 'Hl andJ15 are provided with individual operating arms or levers 16 and TI, respectively, adapted to be operated in sequence by cams 'i8 and 19, respectively, and carried on the inside of a housing 8B attached to the pedestal 52.Y

The operation of the tilt control means of With substantially no tilt between the pedestal or post 52 and the carriage 56 or boom l0, the switch operating parts will be in the position illustrated in Fig. 5 of the drawings. Whenever tilting action takes place between the post 52 and the carriage 55 or boom l0, the operating ring 63 will press down-on the outwardly and downwardly extend- .ing arms of one or more of the bell crank levers 156; This action will, of course, tend to raise the ring 68 by the actuating levers, pivoting it on the diametrically opposite side where it will rest on the inwardly extending arms of the opposite bell crank levers 66.

This pivotal movement of the ring 68 will be transferred by rods 69 to pull upwardly on thel rod 12 and swing the switch lever 'i3 upwardly about its pivot. This upward swinging will elevate the two switches M and 15 so that upon a predetermined tilting movement, one oi" said switches 1li, 'i5 will be actuated by virtue of its l lever or a-rm 16 or 11 engaging a cam T3 or le. Further tilting movement will be required to opcrate the other switch 'i4 or 15, thus providing the initial signal or alarm condition previously described, followed by the nal warning or alarm or the actual shutting down of the apparatus.

It is evident that the lever 'I3 and thus the two control switches 'le and 'i5 will be opera-ted on a predetermined tilt between the mast or pedestal 52 and the boom i0 or carriage 55,

regardless of the particular direction in which this tilt takes place, since the skirt like bell cranks 65 completely surround the mast or pedestal 52. Obviously, within certain broad `aspects of the invention, one of the switches cure by Letters Patent of the United States is:

1. A stacker including an elongated boom having conveyor mechanism thereon adapted to convey and discharge material, traction means operable to travel directly upon and over irregularly undulated ground and swing said boom in a generally horizontal'movement, said traction means including an elongated upstanding boom supporting mast, means interconnecting the boom' to the upper end of said mast providing free tilting movement between them and also providing for rectilinear movement of said mast relative to said boom, said interconnecting means including a trackway extending longitudinally along said boom, a carriage having wheels rolling on said trackway, means cooperating with said trackway to maintain said carriage and boom in a relatively fixed horizontal position while providing for rectilinear movement of said carriage relative to said boom, mechanism providing a substantially universal connection between said carriage and the top of said mast, said universal connection mechanism including cooperating concave-convex` surface forming bearing means, switch means operable whenever said carriage reaches va predetermined position on said boom, and switch means operable on a predetermined tilting lof said mast.

2. A stacker including an elongated boom having conveyor mechanism thereon adapted to convey and discharge material, traction means operable to travel over the ground and swing said boom in a generally horizontal movement, said traction means including an upstanding boom supporting mast, means interconnecting the boom to the upperend of said mast, said means including a carriage, means supporting said boom from said lcarriage while providing for limited rectilinear movement between them, means interconnecting said carriage and said mast for relative tilting movement, and switch means including a suspended flexible tube and a pair of ring contactors therein operable on a predetermined tilting of said mast relative to said carriage.

3. A stacker including an elongated boom having conveyor mechanism thereon adapted to convey and discharge material, traction means operable to travel directly upon and over irregularly undulated ground and swing said boom in a generally horizontal movement, said traction means including an elongated upstanding boom supporting mast, means interconnecting the boom to the upper end of said mast, said means including a carriage, means supporting said boom from said carriage while providing for limited rectilinear movement between them, switch means operable whenever said carriage reaches a predetermined position relative to said boom,

and means interconnecting said carriage and said mast.

boom supporting mast, means interconnecting the boom to' the upper end of said mast including a universally tiltable mechanism, and dual switch means operable to `close one pair of contacts on a predetermined tilting of said mast and to close a second pair of contacts on a greater tilting thereof, said switch means including three concentric conducting rings normally held in spaced relation and sheathed in a supporting tube of insulating material.

5. A stacker including an elongated boom having conveyor mechanism thereon adapted to convey and discharge material, traction means operable to travel over the ground and swing said boom in a generally horizontal movement, said traction means including an upstanding boom supporting mast,vmeans interconnecting the boom vto the upper end of said mast including a universally tiltable mechanism and dual switch means operated automatically in response to apredetermined lmovement of said universally tiltable mechanism to operate one pair of contacts. and upon further movement of said universally tiltable mechanism to operate a second pair of contacts.

Y6. A stacker includingvan elongated boom having conveyor mechanism thereon adapted tov conveyand discharge material, traction meansA operable to travel directly upon and over irregularly undulated ground and swing said boom in a-generally horizontal movement, said traction means including an elongated upstanding boom supporting mast, means interconnecting the Iboom to the upper end of said mast including a.' universally tiltable mechanism, and switch means operated automatically in response to a predetermined tilting of said mast with respect to said boom to operate a pairof contacts.

I' 7; A stacker including an elongated boom having conveyor mechanism thereon adapted to convey Aand discharge material, traction means operable to travel over the, ground and swing said boom in a generally horizontal movement,V

ing `conveyor mechanism thereon adapted tov convey" and discharge material, traction means operablejto travelover the vground andv swing saidboom ina `generally horizontal movement, said traction means including an. upstanding boom Ysupporting mast, means interconnecting theboorn to the upper end ofusaid mast including a, `universally tiltable mechanism, switch means operable upon a predetermined tilting of said mast, actuating -mechanism for said means including-a normally horizontal ring carried by saidboorm a plurality of pivoted bell crank levers carriedfby said vmast and having arms Aextending downwardly skirt like around said mast and surrounded 'by said ring, means operating said switchmeansy when any of said bell crank levers is pivoted a predetermined amo-unt,and a second'` switch means operable by further tilting of said mast. r v 9. A stacker including an elongated boom havi'ngil conveyor mechanism thereon adapted to convey and discharge materiaL- means mounting 'fone end of said boom for movement4 aboutl an'- upright and ahorizontal axis, traction means operable to travel over an uneven,V surface and swing said boom laterally while supporting it,

said traction means including an upstanding means and mechanism for operating it upon va predetermined tilting of said mast including ring means, means carrying said ring means whereby the latter follows the movement of said carriage and surrounds said mast, and means on said mast adapted to engage said ring means when said mast. is tilted said predetermined amount.

l0. A stacker including an elongated boom having conveyor mechanism thereon adapted to convey and discharge material, means mounting one end of said boom for movement about an upright and `a horizontal axis, traction means operable to travel over an uneven surface and` swing said boom laterally while supporting it,"

said traction means including an upstanding boom supporting mast, means interconnecting the boom to the upper end of said mast including a carriage movable rectilinearly with respect to said boom and universally tiltable mechanism.;

switch means andmechanisrn for operatingt rupon a predetermined tilting of said mast inf'k cluding ring means, means carrying said ring means whereby the latter follows the movementV of said carriage and surrounds said mast, andv meanson said mast adapted to engage said ring means when said mast is `tilted said predetermined amount,

' 1l. A stacker including an elongated f boom having-conveyor mechanism thereon adapted tov convey and discharge material, means mounting oneendoi said boom for movement about an upright and a horizontalv axis, traction means operable to travel over man uneven surface. and,

swing-said bociniateraiiy wniie supporting it, said` traction means including an upstanding boom supporting mast, means interconnecting the boo-m to the upper end of said mast includ- Ving a universally tiltable mechanism, switch means and mechanism for operating it upon a predetermined tilting of, said mast including ring means, means carrying said ringmeans whereby the latter follows the movement of said universally tiltable mechanism and surrounds said mast, and means on said mast adapted to engage said ring means when said mast is tiltedsaid predetermined amount;

l2. A stacker including an elongated convey and discharge material, means mounting one end of said boomv for movement about an upright and a horizontal axis, traction meansj operable to travel over'an'uneven surface and swing said boom laterally whilesupportingr it, said traction means including an fupstanding boom supporting mast, means interconnectingV carriage,l and means adaptedto engage said lastv named means when said mast is tilted saidpredetermined amount.

A stacker including an elongated boom having conveyorj mechanism thereon adapted to convey and'discharge material, means mounting one end of said boom for movement about an upright anda horizontal axis, traction means operable 4to travel over an uneven surface and swing said'boorn laterally while supporting it,

A ,Y r boom` having conveyor mechanism thereon adapted to said' traction means including an upstanding boom supporting mast, means interconnecting the boom to the upper end of said mast including a carriage movable rectilinearly with respect to said boom and universally tiltable mechanism, switch means and mechanism for operating it upon a predetermined tilting of said mast including means carried to follow the movement of said carriage, and means adapted to engage said last named means when said mast is tilted said predetermined amount. Y

14. A stacker including an elongated boom having -conveyor mechanism thereon adapted to convey and discharge material, means mounting one end of said boom for movement about an upright and a horizontal axis, traction means operable to travel over an uneven surface and swing said boom laterally while supporting it, said traction means including an upstanding boom Supporting mast, means interconnecting the boom to the upper end of said mast including a universally tiltable mechanism, Switch means and mechanism for operating it upon a predetermined tilting of said mast including means carried to follow the movement of said universally tiltable mechanism, and means adapted to engage said last named means when said mast is tilted said predetermined amount.

l5. A stacker including an elongated boom having conveyor mechanism thereon adapted to convey and discharge material, means mounting one end of said boom for movement about an upright and a horizontal axis, traction means operable to travel over an uneven surface and swing said boom laterally while supporting it, said traction means including an upstanding boom supporting mast, means interconnecting the boom to the upper end of said mast including a carriage movable rectilinearly with respect to said boom through a limited travel and universally tiltable mechanism, and switch means adapted to be actuated by said carriage when either limit of travel of said carriage is reached.

16. A stacker including an elongated boom having spaced longitudinally extending rails and conveyor mechanism thereon, means mounting one end of said boom for movement about an upright and a horizontal axis, boom supporting means operable to travel and swing laterally with said boom including an upstanding boom supporting mast, means interconnecting the boom to the upper end of said mast including a carriage movable rectilinearly between said rails through a limited travel and universally tiltable mechanism, switch means adapted to be actuated when either limit of travel of said carriage is reached, a switCh Vand mechanism for operating it upon a predetermined tilting of said mast including means carried by said carriage, and means adapted to engage said last named means when said mast is tilted said predetermined amount.

17 A stacker including an elongated boom having spaced longitudinally extending rails and conveyor mechanism thereon, means mounting one end of said boom for movement about an upright and a horizontal axis, boom supporting means operable to travel and swing laterally with said boom including an upstanding boom supporting mast, means interconnecting the boom to the upper end of said mast including a carriage mov, able rectilinearly betweenv said rails through a limited travel and universally tiltable mechanism, a, switch and'mechanism for operating it upon a predetermined tilting of said mast including means carried by said carriage, and means adaptthem,

ed to engage saidv last named means when said,

mast is tilted said predetermined amount;

18. A stacker including an elongatedboom having spaced longitudinally extending .Tails and conveyor mechanism thereon, means mounting one end of said boom for movement about an upright and a horizontal axis, boom supportingA means operable to travel and swing laterally with said boom including an upstanding boom supporting mast, means interconnecting the boom to the` upper end ofrsaid mast including a carriage movable rectilinearly between said rails through a limited travel and universally tiltable mechanism, and switch means adapted to be actuated when either limit of travel of said carriage is reached.

19. Mechanism for supporting a stacker boom including a support, means above said support.

adapted to be connected to said boom, means interconnecting said support and the means thereabove providing free tilting movement between them, said interconnecting means including mechanism providing a substantially universal connection between said support and the means` movement of said means above said support, and.

means associated with said support for moving said contact rings into engagement when said support is tilted said predetermined amount.

20. Mechanism for supporting a stacker boom including a support, means above said support.

adapted to be connected to said boom, means interconnecting said support and the means thereabove providing free tilting movement between said interconnecting means including mechanism providing a substantially universal connection between said support and the means.

thereabove, a switch and mechanism for operating it upon a predetermined tilting of said support with respect to said boom including mechanism supported to follow the movement of said means above said support, and mechanism associated with said support for engaging said supported mechanism when said support is tilted said predetermined amount,

21,. Mechanism for supporting a, stacker boom including a support, means above said support adapted to be connected to said boom, means interconnecting said support and the means thereabove providing free tilting movement between them, said interconnecting means including mechanism providing a substantially universal connection between said support and the means thereabove, a switch and mechanism for operating it upon a predetermined tilting of said support with respect to said boom including a ring surrounding said support, and bell crank means associated with said support adapted to be moved when said support is tilted said predetermined amount to operate said switch.

22. Mechanism for supporting a stacker boom including a pair of spaced track members adapted to carry the boom to be supported, a carriage, means on said carriage engaging said spaced track members whereby said carriage may move between said spaced track members, a support below said carriage, and mechanism interconnecting said carriage and support providing a substantially universal connection between them, said interconnecting means including cooperat- 13 ing concave-convex surface forming bearing Number means. 855,425 STANLEY M. MERCIER. 1,265,673 1,458,859 REFERENCES CITED 5 1,512,382 The following references are of record in the le of this patent:

Number UNITED STATES PATENTS 491,134 Number Name Date 10 478,375 v806,804 Hamilton Dec. 12, 1905 504.108

Name Date Arden May 28, 1907 Kjelstad May 7, 1918 Soderberg June 12, 1923 Walsh Oct. 21, 1924 FOREIGN PATENTS Country Date France Jan. 23, 1919 Germany Apr. 8, 1927 Germany Jan. 31, 1929 

